Prevalence of Ixodid Tick Infestation Among Small Ruminants in Ethiopia: A Systematic Review and Meta-Analysis.

Abstract

BACKGROUND: Tick infestation and tick-borne diseases remain a major threat to small ruminant production in Sub-Saharan Africa. In Ethiopia, favourable ecological and climatic conditions promote the survival of ixodid ticks, yet no systematic evidence has summarized their overall prevalence in sheep and goats. METHODS: Following the PRISMA 2020 guideline, a systematic search was conducted in databases (ScienceDirect, Web of Science, Scopus, PubMed, Wiley Online Library and African Journals Online) and other sources (Google Scholar and Google Engine). Studies published between January 2012 and August 2023 were included. A random-effects model was applied to estimate pooled prevalence with 95% confidence interval (CI). Heterogeneity was quantified using the Istatistic, and sources of heterogeneity were explored via subgroup analyses and a Galbraith plot. Publication bias was evaluated using funnel plots and Egger's test. RESULTS: Seventeen studies involving 11,284 small ruminants (4787 sheep and 6497 goats) from seven regions of Ethiopia were included. The pooled prevalence of ixodid tick infestation was 49.95% (95% CI: 37.67-62.22). Infestation was slightly higher in sheep (50.88%; 95% CI: 38.99-62.77) than in goats (46.59%; 95% CI: 30.18-63.00), although the difference was not statistically significant. Among 21,429 ticks identified, Rhipicephalus (Boophilus) was the most prevalent genus (52.8%), followed by Amblyomma (34.9%) and Hyalomma (12.2%), while Haemaphysalis was the least common (0.02%). Regional variation was considerable, with the highest prevalence in the Somali region (81.9%) and the lowest in Afar (36.6%). CONCLUSION: Ixodid ticks are highly prevalent among small ruminants in Ethiopia and pose a continuing risk to productivity and health. Control strategies should prioritize Rhipicephalus (Boophilus) and target high-prevalence regions such as Somali and Dire Dawa. Future research should investigate breed susceptibility, disease associations and integrated control options.